How to show Xamarin.Forms TreeView (SfTreeView) in popup using Rg.Plugin.Popup framework ?

You can load the Xamarin.Forms SfTreeView inside the popup using the Rg.Plugin.Popup framework. Please follow the steps below to work with Rg plugin popup.

You can also refer the following article.

https://www.syncfusion.com/kb/11316/how-to-show-xamarin-forms-treeview-sftreeview-in-popup-using-rg-plugin-popup-framework

Step 1: Install the Rg.Plugin.Popup Nuget package in your shared code project.

Step 2: Initialize the popup plugin on each platform.

In Android, initialize the plugin on the MainActivity.cs page. Also, override the OnButtonPressed method and invoke the SendBackPressed for back button to work with the plugin.

namespace TreeViewXamarin.Droid
{
    [Activity(Label = "TreeViewXamarin", Icon = "@mipmap/icon", Theme = "@style/MainTheme", MainLauncher = true, ConfigurationChanges = ConfigChanges.ScreenSize | ConfigChanges.Orientation)]
    public class MainActivity : global::Xamarin.Forms.Platform.Android.FormsAppCompatActivity
    {
        protected override void OnCreate(Bundle savedInstanceState)
        {
            TabLayoutResource = Resource.Layout.Tabbar;
            ToolbarResource = Resource.Layout.Toolbar;
 
            base.OnCreate(savedInstanceState);
            Rg.Plugins.Popup.Popup.Init(this, savedInstanceState);
            global::Xamarin.Forms.Forms.Init(this, savedInstanceState);
            LoadApplication(new App());
        }
        
        public override void OnBackPressed()
        {
            if (Rg.Plugins.Popup.Popup.SendBackPressed(base.OnBackPressed))
            {
                // Do something if there are some pages in the `PopupStack`
            }
            else
            {
                // Do something if there are not any pages in the `PopupStack`
            }
        }
    }
}

In iOS, initialize the plugin on the AppDelegate.cs page.

namespace TreeViewXamarin.iOS
{
    [Register("AppDelegate")]
    public partial class AppDelegate : global::Xamarin.Forms.Platform.iOS.FormsApplicationDelegate
    {
        public override bool FinishedLaunching(UIApplication app, NSDictionary options)
        {
            global::Xamarin.Forms.Forms.Init();
            SfTreeViewRenderer.Init();
            Rg.Plugins.Popup.Popup.Init();
            LoadApplication(new App());
 
            return base.FinishedLaunching(app, options);
        }
    }
}

In UWP, initialize the plugin on the App.xaml.cs page.

protected override void OnLaunched(LaunchActivatedEventArgs e)
{
    ...
    if (rootFrame == null)
    {
        // Create a Frame to act as the navigation context and navigate to the first page
        rootFrame = new Frame();
 
        rootFrame.NavigationFailed += OnNavigationFailed;
 
        Rg.Plugins.Popup.Popup.Init();
        Xamarin.Forms.Forms.Init(e);
 
        if (e.PreviousExecutionState == ApplicationExecutionState.Terminated)
        {
            //TODO: Load state from previously suspended application
        }
        }
        ...
}

Step 3: Use the command to show the popup using PopupNavigation services in the ViewModel class and bind the command to the button.

<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:local="clr-namespace:TreeViewXamarin"
             x:Class="TreeViewXamarin.MainPage">
 
    <Button Text="Show Popup" 
            Command="{Binding ShowPopupCommand}" 
            HeightRequest="50" 
            WidthRequest="150"
            HorizontalOptions="Center" 
            VerticalOptions="Center"
            BindingContext="{local:FileManagerViewModel}"/>
</ContentPage>

Defining the command in the ViewModel.

public Command ShowPopupCommand { get; set; }
 
public FileManagerViewModel()
{
    ShowPopupCommand = new Command(OnShowPopupClicked);
    GenerateSource();
}
private async void OnShowPopupClicked(object obj)
{
    await PopupNavigation.Instance.PushAsync(new TreeViewPopupPage());
}

Step 4: Create a new page as PopupPage and add SfTreeView to PopupPage.Content.

<pages:PopupPage xmlns:pages="clr-namespace:Rg.Plugins.Popup.Pages;assembly=Rg.Plugins.Popup" 
                 xmlns="http://xamarin.com/schemas/2014/forms"
                 xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
                 xmlns:local="clr-namespace:TreeViewXamarin"
                 xmlns:syncfusion="clr-namespace:Syncfusion.XForms.TreeView;assembly=Syncfusion.SfTreeView.XForms"
                 x:Class="TreeViewXamarin.TreeViewPopupPage">
 
    <pages:PopupPage.BindingContext>
        <local:FileManagerViewModel x:Name="viewModel"/>
    </pages:PopupPage.BindingContext>
 
    <pages:PopupPage.Content>
        <syncfusion:SfTreeView x:Name="treeView" ChildPropertyName="SubFiles" ItemTemplateContextType="Node" ItemsSource="{Binding ImageNodeInfo}" AutoExpandMode="AllNodesExpanded" VerticalOptions="Center" BackgroundColor="White" Margin="20,40" >
            <syncfusion:SfTreeView.ItemTemplate>
                <DataTemplate>
                    <Grid x:Name="grid" >
                        <Grid.ColumnDefinitions>
                            <ColumnDefinition Width="40" />
                            <ColumnDefinition Width="*" />
                        </Grid.ColumnDefinitions>
                        <Grid Padding="5,5,5,5">
                            <Image Source="{Binding Content.ImageIcon}" VerticalOptions="Center" HorizontalOptions="Center" HeightRequest="35" WidthRequest="35"/>
                        </Grid>
                        <Grid Grid.Column="1" RowSpacing="1" Padding="1,0,0,0" VerticalOptions="Center">
                            <Label LineBreakMode="NoWrap" Text="{Binding Content.ItemName}" VerticalTextAlignment="Center"/>
                        </Grid>
                    </Grid>
                </DataTemplate>
            </syncfusion:SfTreeView.ItemTemplate>
        </syncfusion:SfTreeView>
    </pages:PopupPage.Content>
</pages:PopupPage>

Output